Safety device for a gas valve

ABSTRACT

A safety device for a gas valve includes a valve seat, a valve cap, a press bar, an electronic valve, and a thermocouple. The valve cap comprises a passage interconnected with a main gas channel and a gas ignition channel. The passage is formed with a neck. A valve body provided in the gas ignition channel comprises a push bar. The press bar and the electronic valve are disposed at respective sides of the neck. When the press bar is pushed to engage with the neck, an elastic block provided on the electronic valve retreats from the neck and a switch plate provided on the elastic block moves simultaneously to push the push bar of the valve body upward so as to open the gas ignition channel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a safety device for a gas valve, in particular an electronic valve secured to one end of a passage in a valve cap to avoid signal from the electronic valve being disrupted.

2. Description of the Related Prior Art

A conventional gas stove has a safety valve to control gas passage by detecting the temperature in case the fire is distinguished. As shown in FIG. 6, the safety valve comprises a valve seat A and a valve cap B. The valve seat A comprises a main gas inlet A1 and a main gas outlet A2 at respective sides of the valve seat A. The valve seat A comprises a valve body A3 to open or to close the main gas inlet A1 and the main gas outlet A2. The valve cap B comprises a gas inlet B1 and a gas outlet B2 at respective sides of the valve cap B. The valve cap B further comprises an electromagnetic valve B3. The electromagnetic valve B3 comprises a retractable block B7 at the bottom and a press bar B4 at the top. The press bar B4 protrudes from the valve cap B. By pressing the press bar B4 or the magnetic effect of the electromagnetic valve B3 to control the connection of the gas inlet B1 and the gas outlet B2. A thermocouple B5 is provided at outside of the valve cap B. The thermocouple B5 is connected to a temperature sensor to detect the temperature of the fire source. A signal wire B6 is connected to the electromagnetic valve B3 in the valve cap B to detect signal from the thermocouple B5 so as to control the retractable block B7 to extend or to shrink.

To operate the device, as shown in FIG. 7, the press bar B4 is pressed and held down, which forces the electromagnetic valve B3 to move downward in the valve cap B. The electromagnetic valve B3 and the retractable block B7 will shrink, thus the gas inlet B1 and outlet B2 are in an open status and gas may be directed through to light the fire source. Because the press bar B4 is still in a press-down status, the retractable block B7 of the electromagnetic valve B3 move downward to push the electromagnetic valve A3. Thus, the main gas inlet A1 and the main gas outlet A2 are in a closed status.

Upon the temperature of the fire source reaches to a predetermined value, as shown in FIG. 8, the thermocouple B5 transmits a signal to the electromagnetic valve B3 to suck the retractable block B7. By releasing the press bar B4, the electromagnetic valve B3 and the retractable block B7 will no linger extend, thus the retractable block B7 is released from the valve body A3. The main gas inlet A1 and the main gas outlet A2 are in an open status, and gas flows through to the destination.

In case the fire is extinguished to drop the temperature, a signal is transmitted from the thermocouple B5 to the electromagnetic valve B3 and to extend the retractable block B7 out. The retractable block B7 engages with the valve body A3 again, thus the gas inlet A1 and outlet A2 are in a closed status and the gas supply is terminated, as shown in FIG. 6.

However, the electromagnetic valve B3 of the gas safety valve moves up and down in the valve cap B. This movement causes the signal wire B6 to loose after a certain period of time. The other disadvantage is that the press bar B4 of the electromagnetic valve B3 seats direct on the top of the valve cap B, this position is not able to be changed.

SUMMARY OF THE INVENTION

According to the invention there is provided a safety device for a gas valve comprising a valve seat, a valve cap, a press bar, an electronic valve, and a thermocouple. The valve seat comprises a main gas channel. The valve cap is secured to the valve seat and comprises a gas ignition channel and a valve body controlling the opening and closing of the gas ignition channel. The press bar is disposed in the valve cap. The electromagnetic valve is secured to the valve cap and comprises an elastic block at one end. The elastic block is controlled by the press bar and the electromagnetic valve to move. The thermocouple is secured to outside of the valve cap and connected with the electromagnetic valve. The valve cap comprises a passage to interconnect with the main gas channel and the gas ignition channel. The passage is formed with a neck. The valve body in the gas ignition channel comprises a push bar extending into the passage. The press bar moving along the passage has one end to engage with the neck. The electromagnetic valve is secured to another end of the passage. The elastic block of the electromagnetic valve is to engage with or retreat from the neck. The movement of the elastic block links the push bar of the valve body to control the opening and the closing of the gas ignition channel.

The elastic block of the electromagnetic valve comprises a switch plate in an undulate shape. The switch plate is to contact with the push bar of the valve body.

The press bar is transversely disposed in the valve cap, and the valve seat and said valve cap are formed with threaded holes around circumferential edges to receive fasteners therein for secure purpose. The valve cap may be swung to change its position in relation to the valve seat to change the position of the press bar.

The present invention has the following advantages:

-   -   1. The electromagnetic valve is secured to the passage of the         valve cap, so the electromagnetic valve is in a fixed status.         When the press bar is pressed, the electromagnetic valve will         not move, so that the electromagnetic valve and thermocouple can         maintain a stable and steady status.     -   2. There is no signal wire between the electromagnetic valve and         the thermocouple, thus no wire will be torn or pulled to loose.     -   3. The press bar is transversally disposed in the passage of the         valve cap. The position of the valve cap can be changed in         relation to the valve seat, so that the press bar can be changed         in four different ways. It is easy to install the present         invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the present invention;

FIG. 2 is a cross-sectional view of the present invention,

FIG. 3 is a cross-sectional view of the present invention showing that a press bar is pushed down;

FIG. 4 is a cross-sectional view of the present invention showing that an electromagnetic valve is sucked inwardly and a press bar is returned to its original position;

FIG. 5 is a perspective view of the present invention showing adjustment of the position of a valve cap and a valve seat;

FIG. 6 is cross-sectional view of a prior art;

FIG. 7 is a cross-sectional view of the prior art showing that a press bar is pushed down; and

FIG. 8 is a cross-sectional of the prior art showing that the press bar is released.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1 and 2, the present invention comprises a valve seat 1, a valve cap 2, a press bar 3, an electromagnetic valve 4 and a thermocouple 5.

The valve seat 1 comprises threaded holes 11 around the circumferential edges and a main gas channel. The main gas channel includes a gas sub-channel inlet 12, a gas sub-channel outlet 13, a first channel 14 and a second channel 15.

The valve cap 2 is secured to the valve seat 1 and comprises threaded holes 21 around the circumferential edges for fasteners 22 to insert therein. The valve cap 2 further comprises a passage 23 interconnected with the first channel 14 and the second channel 15 of the valve seat 1. The passage 23 is formed with a neck 24 at the center section. One end of the passage 23 is provided with a stop edge 25 at a proper position. The top of the passage 23 is provided with a chamber 26 interconnected with a gas ignition channel. The gas ignition channel includes a gas ignition inlet 27 and a gas ignition outlet 28. The chamber 26 is provided with a valve body 29 to connect or to block the gas ignition channel. The valve body 29 comprises a push bar 291 extending towards the passage 23.

The press bar 3 is transversally disposed at one side of the neck 24 in the passage 23 of the valve cap 2. The press bar 3 comprises a first spring 31 and a second spring 32 urging the press bar 3 to engage with the stop edge 25 and the neck 24 of the passage 23. The front end of the press bar 3 is provided with a washer 33 to engage with or retreat from the neck 24. The washer 33 is urged by the second spring 32 to seal the neck 24 when the washer 33 engages with the neck 24.

The electromagnetic valve 4 is secured to the other side of the neck 24 in the passage 23. One end of the electromagnetic valve 4 is provided with an elastic block 41 to seal the other side of the neck 24. A switch plate 42 is provided on the elastic block 41. The switch plate 42 is in an undulate shape. The switch plate 42 comprises a switch section 43 protruding from the switch plate 42 to push the push bar 291 of the valve body 29.

The thermocouple 5 is connected with a temperature sensor to the fire source. The thermocouple 5 is disposed outside one side of the passage 23 and connected with the electromagnetic valve 4 directly to control the movement of the electromagnetic valve 4.

To practice the present invention, as shown in FIG. 3, the press bar 3 is pressed and held down, thus the first spring 31 is urged to engage with the stop edge 25 in the passage 23 and the second spring 32 urges the washer 33 to engage with the neck 24. The front end of the press bar 3 urges the elastic block 41 of the electromagnetic valve 4 to retreat, and the switch plate 42 moves simultaneously to drive the switch section 43 to push the push bar 291 of the valve body 29 to move upward and open the chamber 26. Thus, the gas ignition inlet 27 is interconnected with the gas ignition outlet 28 to provide gas to the ignition fire. Upon the ignition fire reaches a predetermined temperature, the thermocouple 5 will send a signal to the electromagnetic valve 4 which then activates its magnetic effect to suck the elastic block 41. The pressure force against the press bar 3 is released, and the press bar 3 with the washer 33 is returned to its original position by the first spring 31 and the second spring 32, as shown in FIG. 4. Under this circumstance, the press bar 3 and the elastic block 41 are away from the neck 24. Thus, the first channel 14 and the second channel 15 of the valve seat 1 are connected, and gas flows through the gas sub-channel inlet 12, the first channel 14, the second channel 15 and outward from the gas sub-channel outlet 13 to ignite the stove fire.

When the fire source is extinguished suddenly to drop the temperature of the fire source, the thermocouple 5 will send a signal to the electromagnetic valve 4 to stop sucking the elastic block 41. The elastic block 41 is released to engage with the neck 24 (as shown in FIG. 2). The switch section 43 of the switch plate 42 is also released from urging the push bar 291 of the valve body 29. The push bar 291 of the valve body 29 retreats and seals the chamber 26 to block the gas ignition channel, while the elastic block 41 of the electromagnetic valve 4 engages with the other side of the neck 24 to cut off the main gas channel.

FIG. 5 shows a second embodiment of the present invention. The position of the press bar 3 in the passage 23 of the valve cap 2 may be changed by detaching the fasteners 22 from the threaded holes 11 and 21 of the valve seat 1 and the valve cap 2, then the position of the valve cap 2 is adjusted in relation to the valve seat 1. The valve seat 1 and the valve cap 2 are sealed with the fasteners 22 again, thus the position of the press bar 3 is changed. This change may be done in four different ways. 

1. A safety device for a gas valve comprising: a valve seat, said valve seat comprising a main gas channel; a valve cap secured to said valve seat, said valve cap comprising a gas ignition channel and a valve body controlling the opening and closing of said gas ignition channel; a press bar disposed in said valve cap; an electromagnetic valve, said electromagnetic valve comprising an elastic block at one end, said elastic block being controlled by said press bar and said electromagnetic valve to move; a thermocouple, said thermocouple being secured to outside of said valve cap and connected with said electromagnetic valve, and characterized in that: said valve cap comprising a passage to interconnect with said main gas channel and said gas ignition channel, said passage being formed with a neck, said valve body in said gas ignition channel comprising a push bar extending into said passage, said press bar in said passage having one end to engage with or retreat form said neck, said electromagnetic valve being secured to another end of said passage, said elastic block of said electromagnetic valve being to engage with or retreat from said neck, wherein the movement of said elastic block links said push bar of said valve body to control the opening and closing of said gas ignition channel.
 2. The safety device for a gas valve, as recited in claim 1, wherein said elastic block of said electromagnetic valve comprises a switch plate in an undulate shape, said switch plate contacting with said push bar of said valve body.
 3. The safety device for a gas valve, as recited in claim 1, wherein said press bar is transversely disposed in said valve cap, and said valve seat and said valve cap are formed with threaded holes around circumferential edges to receive fasteners therein for secure purpose, said valve cap may be swung to change its position in relation to said valve seat to change the position of said press bar. 